86 Mr. R. I. Pocock on Neotropical Scorpions. 
has six eyes, with the tail nearly one third longer than the 
trunk (30:21) and the carapace shorter than the anterior 
three caudal segments, it is hardly likely that Karsch’s belief 
will meet with many supporters. If the type in question is 
in the Berlin Museum at all, it will probably, I think, be 
found amongst the specimens in that institution which were 
identified as Opisthacanthus elatus (Gerv.) by Peters. 
But since Scorpio lepturus of Beauvois, with its eight eyes, 
is probably not a Chactas at all, Thorell’s name leptwrus can 
stand for the species to which it was applied, with Thorelliz, 
Karsch, as a synonym; while for the species of Chactas 
which Karsch described as lepturus of Beauvois, I propose 
the name Karschit, in memory of this author’s contribu- 
tions to the elucidation of the species of this genus. 
The British Museum has a single specimen of a scorpion 
from New Granada (Colombia) which I identify as lepturus 
of Thorell. It appears to be young, since it measures only 
35 millim. in length, the tail being 15°5 and the carapace just 
under 5; the anterior three caudal segments taken together 
measure 5°95. 
The carapace is mostly smooth, being finely granular only 
at the sides; the tergites are smooth and polished, the last 
being weakly granular laterally, with two tubercular crests on 
each side. 
The superior keels of the tail are scarcely developed, being 
represented principally by a large posterior tubercle; the 
supero-lateral keels, too, are weak and only very feebly 
granular. 
The hands of the palpi are considerably longer than wide, 
finely granularly rugulose and carinate above. 
The pectinal teeth are 7 on each side. 
Chactas amazonicus, Simon. 
Chactas amazonicus, Simon, Ann. Soc. Ent. Fr. (5) x. p. 384 (1880). 
Described from Pevas (Peru). The Museum has two 
examples (g ? ) from Moyabama, in the same country. 
The male is considerably more granular than the female, 
and has a longer and stouter tail, this organ being more than 
three and a half times the length of the carapace, while in 
the female it is less than three and a half times the length. 
Very characteristic of the species is the tooth at the base 
of the immovable digit and the notch on the movable to receive 
it—features which occur in both sexes. ‘The palpi of the 
male do not appear to be longer than in the female. 
